GENERAL BIOLOGY 



B. PHYSIOLOGY. 



1. Movements: Is Motion continuous? Regular? How is it 

 produced ? Watch process of formation of a pseudopodium. What 

 part does the ectosarc play in the process? The endosarc? Watch 

 an active Amoeba and trace on paper its path of motion. Are there 

 permanent anterior and posterior ends? Does there seem to be 

 any difference in surface tension between the anterior and posterior 

 ends? Are the currents in the endosarc constant? Indicate in a 

 drawing the course of the currents by arrows. Where are the 

 currents swiftest? Where slowest? Are cilia present on any por- 

 tion of the body? 



2. Nutrition: If possible watch the process of taking in food 

 and of its egestion. What does the animal eat? How and where 

 does it take in food ? Are food vacuoles formed ? Is there a 

 definite course of circulation of food within the body? Where is 

 the food digested? How distributed? How are gaseous, liquid 

 and nitrogeneous waste substances expelled from the body? 



3. Reproduction is difficult to observe and may be omitted from 

 notes. 



4. Irritability : Are there any indications that Amoeba is sensi- 

 tive to stimuli ? 



Does Amoeba show any reflex movement? Is its behavior more 

 or less varied than that of Parmecium? 



Enter answers to all these questions in your notes or drawings. 



G. METAZOA 



Metazoa are many-celled animals in which there is differentia- 

 tion into at least two body layers, the Ectoderm and the Endo- 

 derm; the former is the organ of relation, the latter the organ of 

 nutrition ; in addition all have ova and spermatozoa. In all meta- 

 zoa the fertilized ovum undergoes repeated divisions (Cleavage) 

 which lead up to the formation of a hollow sphere of cells 

 (Blastula) and from the latter arises a two-layered condition 

 (Gastrula), the outer layer being the Ectoderm, the inner the 

 Endoderm; between these two a third layer, the Mesoderm, is 

 usually formed. 



Ectoderm and Endoderm consist of cells closely packed to- 

 gether into a layer, such a grouping of cells being called Epithe- 

 lium. Mesoderm, at its first appearance, usually consists of scat- 

 tered cells with large spaces between them, such loosely connected 



[42] 



